The JO-4.03 is described in detail on the pages of the Cryptomuseum:
https://cryptomuseum.com/covert/opto/jo403/index.htm
This video demonstrates the retrieval of a message by the agent.
Device #1 is used by the agent who wants to receive a message. Before 1989, the agent's location was in West Berlin, for example. Device #1 continuously transmits a 16 kHz pilot tone in addition to the agents voice.
Device #2 is running in automatic receive mode. Before 1989, it was located in East Berlin, for example. Device #2 is connected to the auxiliary device (device #3) for evaluation of the pilot tone and control of a tape recorder. Power is supplied via the power supply unit (device #4).
The UHER Report 4000 L was used by the Stasi as a tape recorder. This is connected to the auxiliary device (#3) via a special cable.
The tape was wound to the position with the message to be sent and switched to play. As soon as device #1 is switched to transmit and device #2 receives the 16 kHz pilot tone, the tape recorder is started. It then runs for approx. 30 seconds, the message is played and sent to the agent.
When the transmitter of device #1 is switched off, device #2 transmits an intermittent 1 kHz tone for about 30 seconds.
0 Comments